question_answer

An object is placed in front of a spherical mirror of focal length f. If x and X' respectively represent the distance of the object and the image from the focus, then

A)  \[f=x+x'\]

B)  \[{{f}^{^{2}}}=x\,\,x'\]

C)  \[f=\left| \left. x-x' \right| \right.\]           

D)  f = x ± x' depending upon whether image is real or virtual